The invention relates to an instant thread dyeing method for sewing machines, and more particularly to a method for succesively and instantly dyeing a sewing machine thread with different colors as desired while the thread is used with a sewing machine in a stitching operation.
So far, it has been necessary to prepare so many threads of different colors as required to use for a stitching operation, especially for making pattern stitches and embroidery stitches with a sewing machine, and to selectively use these threads of different colors in dependence upon the kind of pattern stitches or embroidery stitches required. If the sewing machine operator desires to employ a complicated and colorful embroidery stitching with many differently colored threads according to such a conventional manner, the operator is required to interrupt the stitching operation in order to change the sewing machine thread each time a different colored thread is to be used. Such a thread changing operation is considerably troublesome and time-consuming.
Therefore, many attempts have been made for providing a method for dyeing a white or colorless thread with any given color without interrupting the stitching operation. However, there have actually been many difficulties in attaining such a method which will have to satisfy all of the following requirements:
(a) The thread dyeing treatment must be carried out so quickly as to cover a thread consumption speed (i.e., about 1-15 cm/sec) during the stitching operation with a sewing machine;
(b) The thread dyeing treatment will not deteriorate the characteristics of the thread such as slideability and flexibility;
(c) The dyeing effect will be perfect;
(d) The dyeing treatment may be adapted to any kind of thread with any given color; and PA1 (e) The thread dyeing device for carrying out the method must be simple and compact in structure and easy to use.